Pharmacological studies with rescinnamine, a new alkaloid isolated from Rauwolfia serpentina.

Summary1. The pharmacological properties of a new alkaloid, rescinnamine, recently isolated from Rauwiloid®, have been described. Rescinnamine produced typical pharmacological effects of Rauwolfia serpentina: bradycardia, hypotension, and sedation, as well as characteristic alterations in cardiovascular responses, 2. Rescinnamine caused augmentation of pressor response to epinephrine, reversal of pressor response to .hypoxia, diminution of pressor response to bilateral carotid occlusion, and blockade or reversal of primary blood pressure rise elicited by faradization of afferent vagus. 3. The sedative effects of rescinnamine were demonstrated by gross observation in dogs, rats and mice and by prolongation of pentobarbital-induced sleeping time in mice. 4. Rescinnamine produced marked eyelid ptosis in mice and a copious nasal discharge in rats. 5. On a weight basis, rescinnamine appeared to be several times as potent as Rauwiloid® and similar to reserpine. 6. Rescinnamine is the second highly potent alkalo...